I've been somewhat happy with the Nitto DR's.
My 60's times aren't as good as I would like but no problems on the street with them whatsoever. I even got caught in the rain a couple times and they were fine.
The BFG's are a softer compound & the overall design itself tends to make that tire better for drag racing. That is why you'll see guys with the BFG's getting those big smokey burnouts. It takes longer to really heat up the nittos.
The Nittos are a good compromise between street driving & drag tire IMO.
Patrick I think your best bet it to stick with your plan of getting an extra set of rims for the BFG's and mount them when you go to the track, especially as often as you drive your car.
just my .02